21753105 has 16 divisors (see below), whose sum is σ = 37969344. Its totient is φ = 10546880.

The previous prime is 21753079. The next prime is 21753107. The reversal of 21753105 is 50135712.

It is not a de Polignac number, because 21753105 - 2⁵ = 21753073 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21753107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65754 + ... + 66083.

It is an arithmetic number, because the mean of its divisors is an integer number (2373084).

Almost surely, 2^21753105 is an apocalyptic number.

It is an amenable number.

21753105 is a deficient number, since it is larger than the sum of its proper divisors (16216239).

21753105 is a wasteful number, since it uses less digits than its factorization.

21753105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131856.

The product of its (nonzero) digits is 1050, while the sum is 24.

The square root of 21753105 is about 4664.0224056066. The cubic root of 21753105 is about 279.1517910937.

Adding to 21753105 its reverse (50135712), we get a palindrome (71888817).

The spelling of 21753105 in words is "twenty-one million, seven hundred fifty-three thousand, one hundred five".